Re: Ships exploding on GORF problem

Mark is right on this issue. Suspect the one or both of the video RAM
boards. If it isn't those, then you may have a bad custom chip. If you
have the ability to burn an EPROM, I wrote a video memory diagnostic for
Gorf. You can find it here:
http://www.ionpool.net/arcade/tech/GORFMD010.zip.

As for the cocktail/upright jumper, it is JU1. It is located on the Gorf
game board. If you take the board out of the cage and look at the front
of it, the jumper is located slightly below and to the left of the dip
switches. It is just a wire (or lack of one) across two solder pads. It
is actually labeled JU1. If there is a wire, then it is a cocktail, if
there is no wire, it is an upright.

I hope this helps you out. Feel free to email if you have further
questions. :-)

-Commander Dave

"Mark C. Spaeth" <mspaeth@xxxxxxxxxxxxxxxxxx> wrote:
thewiz <grande_illusions2@xxxxxxxxx> wrote:
: Have you experienced this before? I checked both of the ram boards
in my
: wizard of wor and 1 has a problem(was making graphic lines across
the
: screen) so I tried using my WOW ram boards in the gorf to check it,
but
: had the same problem. Must be one of the ram chips on the rom/ram
board,
: I'll start checking those. Do you know what to do with the jumpers
on the
: game board to switch from cocktail to upright? In the manual it says
: Jumper J1 in for cocktail, out for upright, but I don't see any
jumpers.
: At the top end of the game board where the molex pins are, there's a
J2
: stamped on the pcb at the far right of the left set of pins, and J1
at the
: far right of the right set. I'm new at working on these things, I
assumed
: there was probably a jumper wire, but I don't see anything.

Gorf stores all playfield data in the drams, and if it thinks anything
is contacting your ship (whether real or a ram glitch) you die. The
collision detection is done in one of the custom chips, so it's either
the rams or the custom.


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